Ronaldo scored his 13th World Cup goal Thursday and surpassed Pele as Brazil's all-time scoring leader in the competition.
The striker scored with a header in first-half injury time in the defending champion's match against Japan in Group F.
The Real Madrid player is only two goals shy of becoming the tournament's overall leading scorer. He is even with Just Fontaine of France, and has one goal fewer than Gerd Muller of Germany.
Ronaldo had a great chance to put Brazil ahead in the seventh minute after beating a defender inside the area, but his close-range shot was saved by Japan goalkeeper Yoshikatsu Kawaguchi. His right-footer in the 20th was just as dangerous, again being stopped by Kawaguchi.
Brazil was level with Japan 1-1 at halftime in Dortmund.
Ronaldo, playing in his fourth World Cup, has scored 65 goals in 102 matches with Brazil. Pele scored 95 in 114 matches.
Ronaldo was coming off two disappointing performances with Brazil, being held scoreless and twice substituted.
The striker had to deal with a series of distractions since arriving for the World Cup a month ago, including a weight controversy and a string of minor health problems.
Ronaldo admittedly arrived for the World Cup overweight after enduring a series of injuries with Real Madrid earlier in the season.
Brazil's physical trainer Moraci Sant'Anna on Wednesday revealed the striker weighs 90.5 kilograms (199 1/2 pounds), 8.5 kilograms (almost 19 pounds) more than listed by FIFA. Sant'Anna said the striker lost nearly 5 kilograms (11 pounds) since arriving for Brazil's training camp.
Brazil coach Carlos Alberto Parreira has been supporting Ronaldo from the beginning, saying he remains crucial for Brazil and will be a threat after gaining back his rhythm.
Ronaldo was with Brazil when it won the title in 1994 in the United States and 2002 in South Korea and Japan. He could equal Pele's feat as a three-time World Cup winner with another title this year. Pele won it in 1958, '62 and '70.
Ronaldo was crucial in the 2002 tournament, winning the scoring title with eight goals from seven matches. He scored twice in the final against Germany, reports AP.